203190

Appears in sequences

• If n = D0*10^0 + D1*10^1 + D2*10^2 + .. + Dk*10^k define f(n) = D0*0^10 + D1*1^10 + D2*2^10 + .. + Dk*k^10 (e.g. if n = 421 then f(n) = 4*2^10 + 2*1^10 + 1*0^10 = 4098). Sequence gives values of n such that f(n) is divisible by n.at n=18A065110
• Integers x such that for some integer y we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).at n=20A067739